Method and apparatus for making molds



April 5, 1938. A. T. JEFFERY 2,112,910

METHOD AND APPARATUS FOR MAKING MOLDS Filed Oct. 23, 1935 2 Sheets-Sheet1 O0 O9 OC) GO 0 OG CQ O0 O0 April A. T, JEFFERY 2,112,910

METHOD AND APPARATUS FOR MAKING MOLDS Filed Oct. 23, 1935 Y 2Sheets-Sheet 2 A w 1 E44 -j I z: Ill/1,9011,

Patented Apr. 5, 1938 NIETHOD AND APPARATUS FOR MAKING MOLDS Allen T.Jeifery, Dayton, Ohio, assignor to The Dayton Malleable Iron Company,Dayton, Ohio,

a corporation of Ohio Application October 23, 1935, Serial No. 46,267

7 Claims.

This invention relates to the founding art and more particularly to themaking of molds from sand or the like, for use in metal casting.

One object of the invention is the provision of a novel method, andapparatus for carrying out such method, whereby sand molds may beproduced at very high speed, and in an economical manner.

Another object resides in the method of making sand molds in which sandis blown under pressure into a cavity having a wall shaped to thedesired formation to be reproduced, this step being followed by asqueezing action to compress or compact the sand in the cavity.

A further object of the invention resides in an apparatus for makingmolds in which there is a flask supporting portion that can be moved soas to press the flask against a sand supply part, and in which there isprovision for moving the pattern plate with respect to the, flask so asto from the sand supply part.

Other objects and advantages of the invention will be apparent from thefollowing description,

the appended claims, and the accompanying drawings, in which- Fig. 1 isa side elevation of a mold making machine embodying the presentinvention, a portion of the machine being shown in section;

Fig. 2 is a front elevation of the machine;

Fig. 3 is a horizontal section on the line 33 of Fig. 2;

Fig. 4 is an enlarged section on the line 4-6 of Fig. 3;

Fig. 5 is a central vertical section on the line 5-5 of Fig. 1 showingthe relationship of the parts before bringing the pattern plates-and theflask together;

Fig. 6 is a corresponding section but with the parts shown after themold forming cavity has been closed and the sand supplied to the flaskbut before the sand is mechanically compacted;

Fig. 7 is a corresponding section but with the lower pattern plate inits raised position with respect to the flask;

Fig. 3 is a vertical section showing a series of superimposed moldsproduced in accordance with the present invention; and

Fig. 9 is a diagrammatic view of the air supply connections.

Referring to the drawings the apparatus of th present invention isparticularly adapted for the production of sand molds, at a rate far inexcess of that attainable in accordancewith the usual present-daypractice. Ordinarily sand molds,

" compress sand that has been blown into the flask employed in thecasting of metals, have been made by dumping. sand into a flask andmecham'cally pressing or compacting the sand by a pressure board appliedto the sand on the side opposite the pattern or pattern board. Or, inmultiple molding where the pattern is of a simple character, top andbottom pattern boards of complementary form have been employed forcompacting between them the sand that has been applied to the flaskbefore the top pattern board is placed in position. In accordance withthe present invention, however, the sand for making a green sand mold orthe like, for simple or multiple molding, is blown by means of an airstream or streams, through a top plate into a mold cavity provided by aflask, the top plate and a bottom pattern plate, so that the cavity iscompletely filled with sand. The top plate through which the sand isforced into the flask, in the case of multiple molding, is a patternplate that is so formed as to produce an impression that will co operatewith the impression produced by the bottom pattern plate to form thecomplete mold outline. The sand that is blown into the flask is thencompacted as by moving one of the pattern plates towards the other, thesand thus being made hard enough to resist deforming or bulging of thewalls of the mold cavity by the pressure of the poured metal.

As shown, the apparatus comprises a machine frame l having a movabletable i I carrying a flask supporting portion preferably in the form ofa detachable ring or frame I! which is fixed on the table as by means ofsuitable screws IS. The table ll is carried by a movable pressureelement such as the cylinder II, which may be connected to the foundryair line by pipe l so as to be raised or lowered by air pressure. Thecylinder is guided by a fixed piston l1 which is suitably supported onthe baseof the frame III.

The flask iii in which the mold is formed preferably comprises four sidewalls and is rectangular in form, the top and bottom of the flask beingopen. The flask opening corresponds in size and shape with the openingin the ring l2, the flask being adapted to rest upon this ring while thesand is being introduced into it. The lower pattern'plate is also ofsuch length and width as to conform to the opening in the ring i2 and tothe opening in the flask so that the pattern plate can be moved uprelative to the table II into the ring from a normal position as shownin Figs. 5 and 6. In its raised position the top of the pattern plate isabout even with or slightly below the bottom of the flask I8 but duringthe supply of sand to the flask the pattern plate 20 is some distancebelow the level of the bottom of the flask. The pattern plate 20 iscarried by a plunger or piston 22 that operates in a cylinder 23provided in the cylinder M. The supply of air under pressure to the pipe23 causes the piston 22 to be moved upwardly from its normal positionshown in Fig. 5 thus moving the pattern plate upwardly in order tocompact the sandthat has been supplied to the mold cavity provided bythe flask, top pattern plate 33 and bottom pattern plate 23 fitting uponone another.

. When the table II is in its normal or lowered position, the flask II,as shown in Fig. 5, is supported on a flask holding frame 26 which holdsthe flask some distance above the top of the pattern plate 20. Theopposite sides of the flask holding frame 23 are preferably providedwith rotatable rollers 21, see Fig. 4, which operate along tracks 28 inthe form of channel irons extending horizontally the desired distanceabove the top of the table when the latter is in its normal position.These tracks project so that the holder 23 can be run out, carrying theflask II with it, to the position shown in solid lines in Fig. 1. Inthis position the flask may be readily removed from the machine andanother flask placed on the holder in proper position as determined bylocating pins 30 which extend upwardly on the flask holder 28 in suchposition that when the latter is moved inwardly and stops against thestop projection 3|, shown in Fig. 1, the flask will be locatedapproximately in vertical alignment with the pattern plate 20, but somedistance above the pattern plate- This distance is determined by thelength of the arms 32 that are fixed to and project downwardly from thelower side of the tracks 23, and that normally rest against fixed lugsor ledges 33 provided on the machine frame.

When the table II is raised, it moves up until it strikes the under sideof the tracks 23, which it receives in the channels or grooves 29 thatare of such depth as to cause the flask to be picked up by the ring l2.The weight of the flask is thus relieved from the holder 26 when thetable is raised. The holder itself is also picked up by the table II andis moved upwardly with the flask until the upper side of the flask isbrought to bear against the top plate 35 which-is carried by a sandsupply part 36.

Where the apparatus is to be used in simple molding a plurality ofmachines are employed, one for making the cope section and the other formaking the drag section of the mold, and in such case the lower surfaceof the plate 35 is flat on itslower side instead of being provided withthe pattern portions illustrated. Where the apparatus is to be used inmultiple moulding the lower surface of the plate 35 is provided withpattern sections which form a part of the impression. The lower sandretaining wall of the sand supply part 33, in amiaratus for makingeither simple or multiple molds, is fixed a small distance above theplate 35 to provide a space for air removal as will be referred to infurther detail. This sand supply part 36 embodies a horizontally movablecontainer, the top of which registers with a considerable number of airsupply holes 34; The top ofthe container registers with air supply holes34 provided in an air valve designated generally by the referencenumeral 31. Normally the sand distributor 33, which is slidablysupported at its upper end on horizontal tracks on the frame III, isheld by a spring 33 in the position shown in Fig. 2, where the upper end'of the container registers with a sand supply hopper 39. The opening 40at the lower side of sand hopper 39 is normally closed by 'a plate 4|provided on the container and extendingto the left so as to closethesand hopper 33 when the sand container 33 is moved to the right tothe position shown in Fig. 5. This movement is effected against theaction of the spring 33 by means of a suitable air cylinder 42 or thelike. In its left-hand position, the sand flows by gravity from the sandhopper 39, filling the space within thecontainer 36. The latter thenmoves to the right and registers with the air valve 31 so that when airunder pressure is supplied to the top of the sand column, the

' sand will be blown out of a large number of openings 44 that areprovided in the pattern plate 35, the particles of sand being carriedalong by the blast of air issuing from these holes so as to entirelyflll the flask.

Beforethe air is supplied to the upper end of the sand column in thesand container 38, air is supplied under pressure to thepipe l5, raisingthe cylinder l4 and bringing the parts from the position in which theyare illustrated in Fig. 5, to the position shown in Fig. 6. The airpressure is maintained in the table raising cylinder, thus holding thering I2 against the flask I3 and holding the flask l8 against'the lowerside of the top pattern plate 35. Furthermore this air pressure servesto hold the sand container 36 firmly against the lower side of the airdistributing valve 31.

As the table II is raised, the various parts if not already in theirproper position of alignment with one another are brought into exac'tproper alignment, the top pattern plate being positioned plate. Theflask itself is shifted slightly if necessary to its proper positioncentrallpof the pattern plates by means of locating flngers 49 thatproject upwardly from the flask and engage bushings 48 in the toppattern plate, while additional flngers 49 are provided on the table IIfor engagement with bushings 40 in the flask. The two pattern plates arethus located in exact alignment.

With the empty flask 18 held flrmly between the top pattern plate andthe ring l2, and the various parts in the position shown in Fig. 6, theair is turned on so as to subject the sand column in the container 36 tothe factory air line pressure which may be of the order of about poundsper square inch. The sand is thus supplied to the interior of the flask,the various joints between the engaged parts being small enough so thatsand is not lost, although these joints permit the necessary flow of airout of the mold cavity as the sand is fllling into the cavity.Additional means for facilitating the outflow of air from the moldcavity is also provided at places where the sand does not tend to flow,as for example the upper corner portions. At these portions and at otherparts of the upper pattern plate and also in the lower pattern platethere are many holes of about diameter, each hole being filled with ametal shell or ring having one end closed by a fine wire screen which isflush with the lower surface of the pattern plate. Such screenedopenings are indicated at ill in Fig. 6.

After the sand is blown into the flask the sand is compacted, preferablyby moving the bottom pattern plate towards the upper pattern plate.

This is accomplished by supplying air to the pipe lower pattern plate20' bodily upwardly and compressing the sand above it. A stop 52determines the lower position of the pattern plate, while its upperposition is such that its upper face is substantially flush with andpreferably even a little below the level of the bottom of the flask l8in order that a sand to sand joint will be insured when the flask I8 isremoved and placed upon a similar flaskcontaining a similar moldportion. While the upper position of the pattern plate 20 may bepositively stopped the height of the ring [2 may be so chosen that forthe particular air pressure employed the lower pattern plate will havejust enough movement to bring its upper portions 55 and 56 whichcorrespond in form to the lower and upper halves of the article to beproduced. Furthermore these pattern plates also,

incorporate sprue pouring portions 51 and 58, one of which is mountedfor yielding movement. As shown the lower pouring sprue portion 58 isnormally pressed upwardly by a spring 59 so that before the sand isblown into the flask the two sprue portions meet as shown in Fig. 6.Then when the lower pattern plate 20 is moved upwardly with respect tothe table II, the sprue portion 58 merely remains stationary.

After the mechanical compacting of the sand within the flask I 8, theair pressure is relieved from below the piston 22 of the lower patternplate 20. The lower pattern plate is thus moved downwardly in the tableto its normal position, this action being followed by a lowering of thetable itself, by relieving the air pressure below the table cylinder M.The flask is thus lowered, separating the mold from the upper patternplate until the flask weight is taken by the tracks 28, the arms 32 ofwhich come up against the shoulders or abutments 33 that are fixed onthe frame. The lowering movement of the flask then ceases although thetable itself continues to move downwardly, taking the lower patternplate with it. The various parts are thus returned to the positionsshown in Fig. 5. From this position the flask itself is pulledhorizontally so that the flask holder 25 rolls out on the tracks for asgreat a distance as desired, enabling the convenient removal of theflask with the mold contained in it. If the tracks are sufllciently longthe filled flask may be moved far enough to permit an empty flask beingapplied before removing the fllled flask. The air pressureis relievedfrom the cylinder 42 after the table is lowered so that the spring 38returns the sand container 36 to the position shown in Fig. 2 in orderthat more sand can flow into the container ready for the next operation.

The molds thus produced by a large number of flasks I8 of similarconstruction provide a large number of mold sections which may bestacked one upon the other as shown in Fig. 8, with the pins 49 of aflask engaging bushings in the flask above, The top of the upper moldand the bottom of the lower mold are not used but the remaining moldportions provide for simultaneous casting of a great many articles ofthe desired form. The pattern itself may be of any desired shape andadapted for use with or without additional cores. The various pouringsprues of the stacked molds of course register with one another, and thetake-off channels leading from the pouring passage to the variouspatterns in any mold are provided in accordance with proper foundrypractice and produced by one or the other of. the pattern plates.

The various air supply valves may of course be individually operated ifdesired but Fig. 9 shows diagrammatically a form of control in which asingle valve handle can be slowly turned or moved mechanically ormanually to make the necessary air connections in proper sequence sothat air is supplied flrst to the cylinder 42 and then in order tocylinder l4, air valve 31 and piston 22. The air may thenbe supplied toan air vibrator on the top or bottom pattern plate, which isdiagrammatically represented by the reference numeral 60, which vibratesthe plate so that these'paration of the pattern from the mold can bemore readily accomplished without any sticking of the sand. The supplyof air through the air valve 31 continues only for a few seconds, andthe air supply to the valve 31 is then shut off. The air pressure,however, is maintained on the pistons 42, cylinders l4 and piston 22until after the vibrator 60 has been operated if such an air hammer isemployed. The air is released from the various cylinders by successivelycutting off the air supply to the cylinders 23, I4 and 42 in the ordermentioned.

As will now be apparent, the invention makes it possible to make a verylarge number of molds in a very short time and with comparatively littlemanual labor. As it takes only a few seconds to completely flll the moldcavity with sand, and only a very short time for the movement of thevarious cylinders to bring the parts into their proper positions and toreturn the parts back to their original positions, it requires only amatter of a fractional part of a minute for an entire sequence ofoperations productive of a sand mold that can be immediately used forthe reproduction of any desired pattern as finished castings.

While the method herein described, and the form of apparatus forcarrying this method into effect, constitute preferred embodiments ofthe invention, it is to be understood that the invention is not limitedto this precise method and form of apparatus, and that changes may bemade in either without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

1. The method of forming sand to a predetermined shape for use incasting comprising combining a flask and a top pattern plate and abottom pattern plate'to form a cavity, blowing sand into the cavitythrough one of the pattern plates, and moving the other pattern plate tocompress the sand to compact it while maintaining the engagement of thesand blown into the chamber with the top and bottom pattern plates.

2. The method of making multiple molds comprising blowing sand down intoeach-of a series of similar flasks and against top and bottom patternplates to give the desired formation to the sand at the top and bottomof each flask, compressing the sand between the pattern plates by asqueezing action while maintaining such desired formation of the sandand while maintaining the top and bottom pattern plates in contact withthe sand, separating the pattern plates, and stacking similar molds thusformed one upon the other.

3. Apparatus for making molds comprising a table having a flasksupporting portion, a flask adapted for support on said portion, apattern plate, means supporting said plate for movement relatively tosaid table, a. second pattern plate,

means for pressing the flask supporting portim and the flask against thesecond pattern plate. means for supplying sand under pressure to saidflask, and means for moving the flrst mentioned pattern plate to squeezethe sand in the flask.

4. Apparatus for making molds comprising a name, a flask support, aflask adapted for support thereon, means for locating said flask on saidsupport, a bottom pattern plate, a top pattern plate, means for blowingsand through said top pattern plate, means for moving said support toclamp the flask against the top pattern plate, and means for moving saidbottom pattern plate relatively to said support to squeeze the sand insaid flask.

5. The method in multiple molding of forming green sand molds to apredetermined shape for use in casting comprising assembling a flask andtop and bottom pattern plates to form a closed chamber in which sandwill be trapped, blowing sand into the closed chamber to form both topand bottom of the mold to final contour, and moving one of the patternplates toward the other while still maintaining the engagement of thesand blown into the chamber with the top and bottom pattern plates tocompress the sand.

6. The method in multiple molding of forming green sand molds to apredetermined shape for use in casting comprising assembling a flask andtop and bottom pattern plates to form a closed chamber in which sandwill be trapped, blowing sand into the closed chamber through one oi thepattern plates, and moving one of the pattern plates toward the otherwhile stillv main- .taining the engagement of .the sand blown into thechamber with the top and bottom pattern platesto compress the sand.

'l. Apparatus i'or making molds comprising a frame, a sand supply membermounted in said frame, a first pattern 'carried by said sand supplymember, a table mounted in said frame for movement toward and away fromsaid sand supply member and having a flask supporting portion, a flaskadapted for support on said portion, a pattern support carried by andmovable with said table and also having movement relative to said table,a second pattern carried by said support, said flask and said secondpattern cooperating to form a sand receiver, means for moving said tableto filling position to bring said flask and said second pattern intosand receiving relationship with said sand supply member and firstpattern, means for blowing sand through said first pattern into saidreceiving means, and means for moving said second'pattem toward saidfirst pattern to compress the sand while said table remains in fillingposition.

ALLEN I'. JEFFERY.

